On September 15, 2008, Lehman Brothers filed for bankruptcy and ushered in the worst part of the recent financial crisis…. My colleagues at NYU and I have developed measures of systemic risk…. We estimate the amount of capital that a financial institution would have to raise in order to continue to function normally if we have another financial crisis like the one in 2008…. We call this measure SRISK…. Was Lehman at the top of the list in 2008? No. In fact, it was Number 11. The top of the list was Citigroup, which was estimated to need $139 billion…. Lehman would have needed $48 billion in capital. And it was allowed to go under. Interestingly, Washington Mutual, at Number 14, also was allowed to fail.